High CPU consumption on regeneration

Hello,

First I want to express my thanks for making this good plugin!
I use it on all my sites that I have.

Today I noticed that I have a huge problem on one of my sites.
The server load is at its maximum when the photo regeneration starts
Please see this picture >> https://prnt.sc/iVzh9QQcZ8tP

How can I solve this problem? How can I limit for example only 30% of the CPU to be used for image regeneration?
The other thing I’m thinking is – how could I set the regenerations to only happen at night when there aren’t many people on the site?

Thanks!